A conventional optical network mainly adopts a self-healing ring networking mode and has low bandwidth utilization. Furthermore, the conventional optical network is configured statically by a network administrator, and mainly adopts a ring networking, which has a complicated configuration and low bandwidth utilization, and is time consuming. With a requirement for multi-service, high bandwidth, high survivability and rapid connection provision, a network topology would evolve to be mainly a mesh network from being mainly a conventional ring network in the existing systems, and a network connection provision manner should transit to a signaling-based soft permanent connection and switched connection from a statically assigned permanent connection. A novel optical transfer network is referred to be an Automatically Switched Optical Network (ASON) or Generalized Multi-Protocol Label Switching (GMPLS) network.
As for network resources, the ASON/GMPLS must experience the following three processes before providing an available resource and forming a consistent global topology:
1. A vertical synchronization (or local initialization): a local resource of a control plane is initialized, in other words, the control plane acquires a view of the local resource on the control plane, for example, connection points (CPs) of a data plane are mapped to subnetwork points (SNPs) of the control plane, and obtain a resource pool of a local subnetwork point pool (SNPP).
2. A horizontal synchronization (or link discovery): adjacent SNPP links, or referred to as traffic engineering (TE) links, are acquired and formed through a discovery mechanism.
3. A global synchronization: each node obtains a global consistent topology through a route flooding, e.g., an open shortest path first protocol-transport engineering (OSPF-TE).
In the existing systems, the ASON/GMPLS would carry out the above three synchronization processes before providing the available resource and forming the consistent global topology, but in a network running process, some inconsistency may occur between the control plane resource state and the data plane resource state due to a network abnormality or other operations. Moreover, there is no mechanism for detecting the control plane resource state and the data plane resource state in the network running process in the existing systems. Therefore, once an inconsistency occurs, the network would fail, thereby influencing the network stability.